Fregonezi, Vanessa Regiane ResquetiOliveira, Layana Marques de2022-03-222022-03-222021-11-19OLIVEIRA, Layana Marques de. Alterações nos músculos respiratórios na distrofia muscular de Duchenne: suas consequências na apresentação clínica da doença. 2021. 124f. Tese (Doutorado em Fisioterapia) - Centro de Ciências da Saúde, Universidade Federal do Rio Grande do Norte, Natal, 2021.https://repositorio.ufrn.br/handle/123456789/46654Introduction: Introduction: Duchenne muscular dystrophy (DMD) results in progressive weakness of all striated muscles, including respiratory muscles, with consequences on walking, in addition to respiratory difficulties, as the main cause of death. In recent decades, the survival of patients with DMD has increased thanks to a more comprehensive therapeutic approach, especially with measures to assess and early management of pulmonary complications. However, there are still gaps in the understanding of how changes in respiratory muscles can influence thoracoabdominal movement, and the rates of relaxation and contractile properties of the inspiratory muscles in this population. Objective: The main objective of this thesis is to better understand the changes in respiratory muscles in DMD and their consequences on the clinical evolution of the disease with non-invasive measurement instruments. For this, two objectives were outlined: 1) To evaluate how body positioning influences thoracoabdominal asynchrony and the paradoxical inspiratory movement during calm breathing and coughing; 2) To analyze the relaxation rates and contraction properties of the inspiratory muscles in a 6- month follow-up. Furthermore, patients with DMD were divided into 3 groups in order to determine the best parameter related to inspiratory muscle weakness. Methods: This cross-sectional study evaluated individuals with DMD and matched healthy during quite breathing (QB) and spontaneous cough in 3 positions: supine, supine with headrest raised at 45° (45°), and sitting with back support at 80° (80°) using optoelectronic plethysmography (OEP). The TAA was assessed using phase angle (θ) between upper (RCp) and lower rib cage (RCa) and abdomen (AB), as well as the percentage of inspiratory time the RCp (IPRCp), RCa (IPRCa) and AB (IPAB) moved in opposite directions. 2) This is a 6-month longitudinal study where the relaxation rates and contractile properties of the inspiratory muscles were extracted from the nasal inspiratory pressure curve (SNIP), performed in a non-invasive way in individuals with DMD versus a healthy matched group. Results: 1) Fourteen DMD subjects and 11 healthy subjects were included and we found that during coughing, DMD group showed higher RCp and RCaθ (p<.05), RCp and AB θ (p<.05) in supine and 45° positions, and higher RCp and Rcaθ (p=.006) only in supine position compared with controls. Regarding the intragroup analysis, during cough, DMD group presented higher RCp and AB θ (p=.02) and RCa and AB θ (p=.002) in supine and higher RCa and AB θ (p=.002) in 45° position when compared to 80°. ROC curve analyzes were able to discriminate TAA between controls and DMD in RCa and AB θin supine position [AUC: 0.81, sensibility: 78.6% and specificity: 91.7%, p=0.001]. In the second study, 22 DMD were compared to healthy individuals, and had a lower (p<.005) maximum relaxation rate (MRR) and a greater (p<.0005) tau (τ) and a greater (p<.05) half‐relaxation time (1/2 RT) in baseline and after 6 months. The results of the ROC curves showed that MRR, τ, 1/2 RT and SNIP(%pred) parameters were significantly able to discriminate between DMD and controls in baseline and after 6 months. Conclusions: Thus, with this thesis, we can conclude that 1) In DMD, positioning is a determinant in the appearance of abdominal asynchrony and that during coughing, individuals with DMD have thoracoabdominal asynchrony with insufficient emptying and distortion of the chest wall compartments. 2) Relaxation rates of inspiratory muscles are sensitive variables to detect the decline in respiratory function in DMD. Thus, the sitting posture brings greater benefits to these patients, with the generation of higher peaks of cough flow and less asynchrony, as well as the relaxation rates and contractile properties of the inspiratory muscles by SNIP are essential for identifying weakness inspiratory muscle in DMD. Therefore, we suggest that the non-invasive assessment techniques presented in this study be introduced as a complementary assessment for the follow-up and clinical management of this population.Acesso AbertoDistrofia muscular de DuchenneAssincronia toracoabdominalMúsculos respiratóriosdoctoralThesis